"The sweet smell of success" may be over for investors in the fertilizer companies. Harry M. Flavin, vice-president at Merrill Lynch, says the price of the fertilizer stocks has already discounted all the good news. Now, he says, investors should be concerned that cost pressures are mounting on the companies. Still, he notes that supplies will not be overabundant through 1982.

Remember why Exxon Corporation paid $1.2 billion to buy Reliance Electric Company? It was because of Reliance's new energy-saving technology for electric motors. Now, in its annual report, to be released March 24, Exxon is revealing that Reliance has encountered difficulties in the technology and is looking at alternative circuitry to remedy the problems. An Exxon spokesman says the company has no idea when it will be ready.